This invention relates to air ionizers and more particularly to an apparatus and method for producing time-varying quantities of positive and negative air ions.
Individual molecules of the gases that constitute ambient air can acquire electrical charge and become positive or negative ions, depending upon whether a deficiency or an excess of electrons has been imparted to the molecule. Positive and negative ions are commonly present in the ambient air as a result of static electricity discharges and/or other natural causes.
High levels of air ionization can have the beneficial effects of removing particulate contaminants such as smoke particles or pollens from the air by transferring charge to such particles. The charged particles are electrostatically attracted to nearby surfaces that are electrically neutral or oppositely charged and are then deposited against such surfaces. Additionally, air with a high content of negative ions is believed to have beneficial physiological effects on persons who breathe the air.
Air inside buildings tends to become stale and unpleasant to breathe as a result of, in part, the depletion of the ion content in the air. Various conventional air ionizers have been developed to counteract the depletion of ions and also to purify air by causing the precipitation of particulate contaminants out of the air and onto nearby surfaces. Such conventional air ionizers typically include pointed electrodes that are connected to high voltage supplies to produce intense electrical fields adjacent the pointed electrodes. Neutral gas molecules in the vicinity of the intense electrical fields are transformed to positive or negative ions, depending upon the polarity of the high voltages on the electrodes. Electrostatic repulsion from the similarly charged electrodes and air blowers disperse the air ions throughout the room to cause precipitation of particulate contaminants from the air and to promote the beneficial physiological effects reported by some people who breathe the air. Such conventional air ionizers commonly produce predetermined ratios of positive to negative ions (for example, ratio in equal numbers), and such balancing can be maintained in a variety of ways that permit continued self-balancing of generated ions over a wide range of varying operating conditions. Air ionizers of this type are described in the literature. (See, for example, U.S. Pat. No. 5,055,963).
However, such conventional air ionizers typically do not have the capability of generating time-varying quantities of positive and/or negative ions. It is believed that rapid variations in the concentration and polarity of ions in the air over time promote physiologically desirable effects in people who are exposed to such air with modulated ion content.
The apparatus and method in accordance with the present invention produce ions of positive and negative polarity in time-varying manner to promote more physiologically desirable effects in people who are exposed to air with such modulated ion content. In one embodiment, the apparatus of the present invention is particularly suited for room installations and includes electrodes that are spaced apart and are energized to high voltage levels to form intense electrical fields adjacent each of the electrodes. The electrical field adjacent each electrode promotes the generation of positive or negative ions, and in one embodiment of the invention, level controllers are used to vary the concentration of ions of one or other polarity over time.
In one embodiment of the present invention, the level controller provides control signals that control the voltage level at the electrodes to permit positive and negative ions to be generated in quantities that vary aperiodically, randomly, or pseudo-randomly over time intervals (such as one to a few seconds). As a result, the ion concentration may vary rapidly or fluctuate within a range of minimum and maximum levels for one or other polarities.
In another embodiment of the invention, a controller controls generation of positive ions or negative ions in quantities that vary in a manner simulating the ion signature of a selected geographical location.